Adnexal masses are growths that can form in the ovaries or fallopian tubes for different reasons, such as hormonal changes, infection, or cancer. These masses may cause pelvic discomfort, pain, constipation, or no symptoms at all. When adnexal masses are found on scans, they are described in a certain way to indicate if they could represent early-stage cancer, and the word complex is used to refer to these masses. Surgery is often recommended, where the mass is removed and examined under the microscope during surgery in a process called (frozen section analysis); to determine its true nature. It is still difficult to confirm cancer before surgery, and many of these masses turn out to be benign (not cancerous) or borderline (slow-growing tumours). Currently, doctors use open surgery with a cut from at least the belly button to the pubic bone to remove these masses. Patients with a cancer diagnosis will then have more surgical steps including assessment and sampling of various areas inside the abdomen (known as staging surgery) to see how far the cancer has spread. Recovery after open surgery can be long and painful, with a slow return to normal daily activities. The trial investigators know from practice that robotic surgery has replaced open surgery for most benign adnexal diseases and other types of women's cancers, such as womb cancer. Recovery is quicker, with less pain and blood loss, allowing for a faster return to daily activities. This study, MIRRORS-FROZEN (pilot), compares robotic versus the standard open surgery in managing women with complex adnexal masses of eight centimetres or less. The hope is to decrease the need for open surgery in patients with benign or borderline disease and to assess if robotic surgery has similar, worse, or better outcomes for patients with cancer. MIRRORS-FROZEN is funded by Intuitive Foundation and GRACE Charity. The investigators will establish the feasibility of conducting a large multicentre randomized controlled trial in the future comparing certain cancer outcomes between robotic and open surgery.